Vehicle suspension and pneumatic systems

ABSTRACT

A vehicle has a frame, at least one front wheel, at least one front suspension assembly, at least one rear wheel, and at least one rear suspension assembly, a seat, a steering assembly, an engine, and an air intake system fluidly communicating with the engine. At least one of the front and rear suspension assemblies includes an air spring. An air compressor selectively supplies air to the at least one air spring. An inlet of the air compressor fluidly communicates with the air intake system. During operation of the air compressor to supply air to the at least one air spring, the air compressor draws air from the air intake system and simultaneously supplies the air to the at least one air spring. A control unit is electrically connected to the air compressor for controlling an operation of the air compressor.

CROSS-REFERENCE

The present application is a continuation of U.S. patent applicationSer. No. 13/320,841, filed Nov. 16, 2011, which is a national phaseentry of International Patent Application No. PCT/US2010/036658, filedMay 28, 2010, which claims priority to U.S. Provisional PatentApplication No. 61/182,459, filed May 29, 2009, the entirety of all ofwhich is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a suspension system and a pneumaticsystem for a vehicle.

BACKGROUND

In many all-terrain vehicles, as well as in other types of vehicles, thevehicle suspension system often includes a sway bar, also known as ananti-roll bar. The sway bar is used to connect laterally oppositewheels. The sway bar helps reduce the tendency of the vehicle to rollsuch as when the vehicle is turning. However, sway bars add weight andmechanical complexity to the vehicle.

Some vehicles also use air springs in their suspension system. In suchvehicles, a compressor or pressurized gas reservoir is used to supplypressurized air or gas to the air springs. However, in systems using acompressor, dust, dirt, and/or water can often enter the compressoralong with the air. These can cause a malfunction of the compressor andor the air springs over time. This problem is exacerbated when thevehicle is used in off-road conditions, such as for all-terrainvehicles.

Finally, many users of off-road vehicles bring an air compressor withthem when using their vehicle. The air compressor can be used to inflatea flat tire for example, which would otherwise be very difficult due tothe remoteness of the locations where off-road vehicles are used. Theair compressor can also be used to inflate other things such as aninflatable boat. However, in many off-road vehicles, such as all-terrainvehicles, the amount of storage space on the vehicle is limited. As aircompressors can be bulky, storing one on the vehicle takes up asignificant amount of the limited storage space.

SUMMARY

An aspect of a present vehicle provides an air compressor for supplyingair to two air springs used in the suspension system for the wheels. Thetwo air springs fluidly communicate together. The air lines connected tothe air springs are provided with valves. The valves are controlled toprevent air from one air spring from going to the other air spring whenthe vehicle starts to roll. This helps to reduce the tendency of thevehicle to roll. As such, it is no longer necessary to provide a swaybar between the front wheels to control the vehicle's roll.

Another aspect of the present vehicle provides an air compressor forsupplying air to air springs used in the suspension system, wherein theair compressor receives air from the air intake system of the engine ofthe vehicle. As the air intake system of the engine prevents air, dirt,and water from entering the engine, the air intake system also preventsthese from entering the air compressor and air springs.

Another aspect of the present vehicle provides an air compressor mountedto a frame of the vehicle. The air compressor supplies air to airsprings used in the suspension system and to an auxiliary air output.The auxiliary air output can be used to inflate, for example, a tire oran inflatable boat or any other inflatable device or to actuate apneumatic device.

For purposes of this application terms related to spatial orientationsuch as forwardly, rearwardly, left, and right, are as they wouldnormally be understood by a driver of the vehicle sitting thereon in anormal driving position.

Example embodiments of the present vehicle have at least one of theabove-mentioned aspects, but do not necessarily have all of them. Itshould be understood that example embodiments of the present vehicle mayhave other aspects not specifically recited herein.

Additional and/or alternative features, aspects, and advantages ofembodiments of the present vehicle will become apparent from thefollowing description, the accompanying drawings, and the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, as well as otheraspects and further features thereof, reference is made to the followingdescription which is to be used in conjunction with the accompanyingdrawings, where:

FIG. 1 is a right side elevation view of an all-terrain vehicle (ATV) inaccordance with aspects of the present invention;

FIG. 2 is a schematic illustration of a pneumatic system and electricsystem of the ATV of FIG. 1;

FIG. 3 illustrate a display cluster of the ATV of FIG. 1;

FIG. 4 is a right side view of a frame, a suspension system, and thepneumatic system of the ATV of FIG. 1;

FIG. 5 is a close-up view, taken from a front, right side, of an air boxshown in FIG. 4;

FIG. 6 is a close-up view of a rear, right side of the left portion ofFIG. 4;

FIG. 7 is a close-up view, taken from a front, right side, of a portionof the pneumatic system shown in FIG. 4;

FIG. 8 is a close-up view, taken from a rear, left side, of the portionof the pneumatic system shown in FIG. 4;

FIG. 9 is a close-up view taken from a rear, left side, of the portionof the pneumatic system shown in FIG. 4 with the frame removed forclarity;

FIG. 10 is a top view of FIG. 6;

FIG. 11 is a side view of a hose to be connected to an auxiliary airoutput of the pneumatic system;

FIG. 12A is a right side view of a frame, a suspension system, and analternative pneumatic system of the ATV of FIG. 1;

FIG. 12B is a schematic illustration of the alternative pneumatic systemof FIG. 12A and of a corresponding electric system;

FIG. 13 is a schematic illustration of another alternative pneumaticsystem and electric system of the ATV of FIG. 1;

FIG. 14 is a schematic illustration of yet another alternative pneumaticsystem and electric system of the ATV of FIG. 1; and

FIG. 15 is a schematic illustration of an alternative pneumatic systemand electric system of the ATV of FIG. 1.

DETAILED DESCRIPTION

The present invention will be described with reference to an all-terrainvehicle (ATV) 10 having four wheels 18. However, it is contemplated thataspects of the ATV 10 could be used in other types of vehicles, such asside-by-side recreational utility vehicles (RUVs), and/or in vehicleshaving less or more than four wheels 18.

FIG. 1 illustrates the ATV 10. The ATV 10 has a frame 12 (portions ofwhich are shown in FIG. 1) to which is mounted a body 14 and an internalcombustion engine 16 for powering the ATV 10. Also connected to theframe 12 are four wheels 18 with low-pressure balloon tires 20 mountedto rims 22 having a diameter from 25 to 36 cm. It is contemplated thatthe ATV 10 could have only three wheels 18. The low-pressure balloontires 20 are inflated to a pressure of no more than 2 kg/cm² (i.e., nomore than 196 kPa or 28 psi) and are adapted for off-road conditions andtraversing rugged terrain. The ATV 10 further includes a straddle seat24 mounted to the frame 12 for supporting a driver and optionally one ormore passengers.

The two front wheels 18 are suspended from the frame 12 by respectivefront suspension assemblies 26 while the two rear wheels 18 aresuspended from the frame 12 by respective rear suspension assemblies 28,described in greater detail below.

Still referring to FIG. 1, the ATV 10 further includes a steeringassembly 30 which is rotationally supported by the frame 12 to enable adriver to steer the ATV 10. The steering assembly 30 includes ahandlebar 32 connected to a steering column (not shown) for actuatingsteering linkages connected to left and right front wheels 18. Athrottle operator in the form of a thumb-actuated throttle lever 34 ismounted to the handlebar 32. Other types of throttle operators, such asa finger-actuated throttle lever and a twist grip, are alsocontemplated.

A display cluster 36 is disposed forwardly of the steering assembly 30.As seen in FIG. 3, the display cluster 36 has a frame 38 inside whichthree gauges 40, 42, and 44 are provided. The gauge 40 displays thespeed of the ATV 10. The gauge 42 displays the speed of rotation of theengine 16. The gauge 44 is a digital gauge that can display variousinformation regarding the ATV 10, such as oil level, engine temperature,and also information relating to the suspension system and pneumaticsystem of the ATV 10 as described in greater detail below. The displaycluster 36 also has a mode button 46 and a set button 48. The modebutton 46 is used to select which information is displayed on the gauge44. The set button 48 is used to modify the information displayed and/orto provide inputs related to the information displayed on the gauge 44to an electronic control unit (ECU) 50 (FIG. 4) of the ATV 10 asdescribed in greater detail below. It is contemplated that additionalbuttons could be provided on the display cluster 36 or on the handlebar32 to control additional features of the display cluster 36 and/or toprovide additional inputs to ECU 50.

A transmission (not shown) is operatively connected between the engine16 and the wheels 18 as is known in the art. A shifter 52 located nearthe steering assembly 30 enables a driver to select one of a pluralityof drive modes for the vehicle 10. The drive modes include park,neutral, reverse, low, and drive. A speed sensor (not shown) senses thespeed of rotation of one of the shafts (not shown) transmitting powerfrom the transmission to the wheels 18. The ECU 50 sends signals to thevarious components and systems of the engine 16, such as the throttlevalve operator and the fuel injection system, to control the operationof the engine 16 based at least in part on the position of the throttlelever 34. Although shown as having a single ECU 50, it is contemplatedthat the ATV 10 could have a plurality of ECUs each having one or morededicated functions.

Air is supplied to the engine 16 via an air intake system which includesan air box 54 (shown in phantom in FIG. 1, seen in FIGS. 4 and 5). Theair box 54 is mounted to the top of the frame 12 behind the steeringcolumn (see FIG. 5, note the indentation in the air box 54 and theopening in the frame 12 for receiving the steering column). As such, theair box 54 is disposed higher than the top of the wheels 18, thusreducing the likelihood of water entering the air box 54 when the ATV 10travels through a body of water, such as when crossing a river. The airbox 54 is made of two halves 54A, 54B and has a forwardly facing inlet56 for admitting air into the air box 54. The air box 54 has a filter 55(partially shown in dotted lines in FIG. 5) disposed generallyvertically, various chambers and passages to reduce the likelihood ofwater, dirt, and dust entering the engine 16, and for reducing noisefrom the engine 16. The inlet 56 is position on a first side of thefilter. The air box 54 has an outlet 57 disposed on a second side of thefilter 55. The outlet 57 is connected to one or more pipes (not shown)which fluidly communicate the air box 54 with the air intake manifold(not shown) of the engine 16.

Turning now to FIG. 4, the frame 12 has an upper frame member 58 and alower frame member 60 which are connected by a forward frame member 62and two vertical frame members 64 and 66. As can be seen, the air box 54is mounted to the upper frame member 58. The frame 12 is also providedwith various brackets and other elements as would be known to a personskilled in the art, some of which will be described below. U.S. Pat. No.6,799,781 B2, issued Oct. 5, 2004, the entirety of which is incorporatedby reference, describes in more detail frames similar to the frame 12.

As best seen in FIG. 6, each rear suspension assembly 28 consists of aswing arm 68 having one end pivotally connected to the vertical framemember 66 and the other end supporting the axle of its correspondingrear wheel 18. Each rear suspension assembly 28 also has an air spring70 disposed inside of a coil spring 72. Each air spring 70 has one endpivotally connected to the upper frame member 58 via a bracket 74 andthe other end pivotally connected to its corresponding swing arm 68. Theair springs 70 provide a variable spring rate which, as would beunderstood, increases as the air springs 70 are compressed. The range ofthe spring rates provided by the air springs 70 depends on the pressureof the air initially supplied to them as will be described below. It iscontemplated that the air pressure initially supplied to the air springs70 could vary between 0 psi and 85 psi, but higher pressures arecontemplated. It is contemplated that the air springs 70 could be FloatR sport shocks manufactured by Fox Factory Inc. Other types of airsprings are also contemplated. The coil springs 72 provide a spring ratethat is preferably between 7 N/mm and 21 N/mm, and more preferablybetween 9 N/mm and 19 N/mm inclusively. As can be seen in FIG. 4, eachfront suspension assembly 26 consists of an A-arm 76 having one endpivotally connected to the lower frame member 60 and the other endsupporting the axle of its corresponding front wheel 18. Each frontsuspension assembly 26 also includes a coil over shock assembly 78, suchas those currently used on most ATVs, having one end pivotally connectedto its corresponding A-arm 7 6 and the other end connected to the upperframe member 58 via a bracket 80. However, and as will be described withrespect to alternative embodiments below, it is contemplated that thecoil over shock assemblies 78 could be replaced by air springs disposedinside coil springs as in the rear suspension assemblies 28. It is alsocontemplated that only the two front suspension assemblies 26 could beprovided with air springs.

Turning now to FIGS. 2 to 11, a pneumatic system of the ATV 10 andportions of the electrical system of the ATV 10 associated with thepneumatic system will be described.

The pneumatic system includes an air compressor 100 mounted via abracket 102 to the vertical frame member 66 in the space between thevertical frame members 64, 66, the upper frame member 58, and the lowerframe member 60. The air compressor 100 is preferably disposed higherthan a center of the wheels 18 when the ATV 10 is at rest. The aircompressor 100 is powered by the electrical system of the ATV 10 (i.e.the battery or magneto, not shown). It is contemplated that thecompressor 100 could be a mechanical compressor driven by the engine 16.The compressor 100 receives air from the air box 54 via air line 104connected to an outlet 105 on lower half 54B of the air box 54. Theoutlet 105, like the outlet 57, is disposed on a side of the filter 55opposite the side of on which the inlet 56 to the air box 54 is located.Since the air box 54 is disposed higher than the wheels 18, as discussedabove, the likelihood of water entering the air compressor 100 isreduced. An air filter 106 (shown in phantom in FIG. 5) disposed insidethe air box 54 near the in let of the air line 104 further prevents dirtand dust from entering the air compressor 100. It is contemplated thatone of the filters 55 and 106 could be omitted. It is contemplated thatthe inlet of the air line 104 could alternatively be connected at otherpoints along the air intake system of the engine 16.

The outlet of the air compressor 100 is connected to a check valve 108preventing air from flowing back towards the air compressor 100. AT-connector 110 downstream of the check valve 108 splits the air flowbetween air line 112 and air line 114. The air line 112 is connected toan auxiliary air output 116. The auxiliary air output 116 is mounted viaa bracket 118 to the body of the ATV 10 so as to be easily accessible bya user. For example, the auxiliary air output 116 could be located underthe seat 24 and be accessible when the seat 24 is removed or pivoted.Alternatively, the auxiliary air output 116 could be mounted to theframe 12. The auxiliary air output 116 is preferably a “quick-connect”connector of the type typically used in pneumatic applications, such aswith pneumatic tools, including a built-in check valve. An air hose 120,shown in FIG. 11, having a connector 122 which is complementary to theauxiliary air output 116, can be connected to the auxiliary air output116, thus allowing compressed air from the air compressor 100 to be usedfor various applications, such as for inflating a tire for example. Whennot in use, the air hose 120, is disconnected from the auxiliary airoutput 116, and is stored in one of the storage compartments of the ATV10. It is contemplated that the air line 112 could connect the auxiliaryair output 116 directly to the air compressor 100 should the aircompressor 100 be provided with a second outlet, thus eliminating theneed for the check valve 108 and the T-connector 110.

The air line 114 is connected to a T-connector 124. The T-connector 124splits the air flow between air line 126 and air line 134. The air line126 is connected to a low pressure sensor 130. The low pressure sensor130 is electrically connected to the ECU 50 via an electrical wire 132(portions of which are not shown in FIGS. 4 to 10 for clarity) to send asignal representative of the air pressure between the check valves 108and 128 to the ECU 50.

The air line 134 is connected to a check valve 128. The check valve 128prevents air in the pneumatic system downstream of the check valve 128(i.e. air in the air springs 70) to flow out of the pneumatic systemthrough the auxiliary air output 116 when the auxiliary air output 116is in use. The check valve 128 is connected to a manifold 136.

The manifold 136 is connected via an air line 138 to a high pressuresensor 140 disposed inside the ECU 50. It is contemplated that the highpressure sensor 140 could be disposed outside of the ECU 50. The highpressure sensor 140 is electrically connected to the ECU 50 to send asignal representative of the air pressure in the air springs 70 to theECU 50. Since the air pressure inside the air springs 70 cansubstantially increase when the air springs 70 are being compressed, thehigh pressure sensor 140 can sense air pressures which are much higherthan the low pressure sensor 130 (up to 300 psi for the high pressuresensor 140 vs. up to 100 psi for the low pressure sensor 130, forexample).

The manifold 136 is also connected to the air springs 70. An air line142 connects the manifold 136 to a T-connector 144 which splits the airflow between two air lines 146 connected to the air springs 70 to supplyair to the air springs 70.

The manifold 136 also has an outlet 148 to the atmosphere to release airfrom the air springs 70 or coming for the air compressor 100 to theatmosphere. A solenoid actuated valve 150 is connected to the manifold136 to control the flow of air from the compressor 100 to the outlet 148and the air line 142 (i.e. the air springs 70). The solenoid of thevalve 150 is electrically connected to the ECU 50 via an electrical wire152 (portions of which are not shown in FIGS. 4 to 10 for clarity) suchthat the ECU 50 can send signals to the solenoid to control the positionof the valve 150 as will be described below. It is contemplated that thevalve 150 could be actuated by a different type of actuator.

As can be seen in FIG. 2, the ECU 50 is also electrically connected tothe cluster 36 and the air compressor 100. To set the air pressure inthe air springs 70, the user of the ATV 10 first enters an air pressureselection screen of the gauge 44 using the mode button 46 of the cluster36. The user then selects an air pressure desired in the air springs 70using the set button 48. The desired air pressure corresponds to thedesired air pressure in the air springs 70 when the ATV 10 is at rest.In the example shown in FIG. 3, the user can select one of six presetair pressures. For exemplary purposes only, the six preset air pressuresvary from 5 psi (preset 1) to 80 psi (preset 6) in increments of 15 psi.In FIG. 3, the user has selected preset 3 which corresponds to 35 psi.As can be seen, the gauge 44 displays the selected air pressure. It iscontemplated that instead of labeling the presets with numbers as shown,that the presets could be labeled with qualitative labels regarding thesuspension, such as “smooth”, “firm”, “sport”, etc. It is alsocontemplated that the user could manually put in any desired airpressure within the operating range of the pneumatic system and the airsprings 70. The ECU 50 then determines based on the reading obtainedfrom the high pressure sensor 140 if the air pressure in the air springs70 corresponds to the air pressure selected by the user. If the airpressure in the air springs 70 is too high, the ECU 50 sends a signal tothe solenoid actuated valve 150 to open the outlet 148, thus releasingair from the air springs 70 until the air pressure in the air springs 70corresponds to the selected air pressure. If the air pressure in the airsprings 70 is too low, the ECU 50 sends a signal to the air compressor100 to operate until the air pressure in the air springs 70 correspondsto the selected air pressure.

As would be understood, when the ATV 10 is in motion (as determined bythe speed sensor of the ATV 10), especially over rough terrain, the airpressure inside the air springs 70 constantly fluctuates. Therefore,when the ATV 10 is in motion, the ECU 50 uses an average of the airpressure readings from the high pressure sensor 140 over time todetermine whether the readings obtained would result in the air pressurein the air springs 70 corresponding to the selected air pressure if theATV 10 was at rest. It is contemplated that sensors could also be usedto sense the degree of compression of the air springs 70 to assist inmaking this determination.

Also, during operation of the ATV 10, some of the air could leak out ofthe air springs 70, thus causing the air pressure in the air springs 70to drop below the selected air pressure. When this occurs, the ECU 50sends a signal to the air compressor 100 to operate until the airpressure in the air springs 70 corresponds once again to the selectedair pressure.

When the signal sent from the low pressure sensor 130 to the ECU 50indicates an air pressure that is below the selected air pressure, theECU 50 determines that the auxiliary air output 116 is in use.Accordingly, the ECU 50 sends a signal to the air compressor 100 tooperate until the air pressure reading for the low pressure sensor 130corresponds once again to the selected air pressure. However, the ECU 50will stop the operation of the air compressor 100 if it operates for toolong, which may damage the air compressor 100. This could occur forexample when using the auxiliary air output 116 to inflate somethinghaving a large volume while the selected air pressure is low. It iscontemplated that a message regarding this temporary interruption couldbe displayed on the gauge 44.

Turning now to FIGS. 12A to 15, various alternative embodiments of thepneumatic system and electrical system described above will bedescribed. For simplicity, elements of these embodiments which aresimilar to those described above have been labeled with the samereference numerals and will not be described again in detail.

In the embodiment shown in FIGS. 12A and 12B, the front suspensionassemblies 26 are provided with two front air springs 70 (air springs#1, 2) and the rear suspension assemblies are provided with two rear airsprings 70 (air springs #3, 4). The manifold 136 has three outlets tothe air springs 70. One of the outlets of the manifold 136 is connectedto a valve 145, which is connected to one of the front air springs 70(air spring #1) via air line 146. Another one of the outlets of themanifold 136 is connected to another valve 145, which is connected toanother one of the front air springs 70 (air spring #2) via another airline 146. The opening and closing of the valves 145 is controlled by theECU 50. By closing one or both of the valves 145, air from one of thefront air springs 70 is prevented from moving to the other one of thefront air springs 70 when the vehicle starts to roll for example. Thishelps to reduce the tendency of the ATV 10 to roll. As such, it is nolonger necessary to provide a sway bar between the front wheels 18 tocontrol the roll of the ATV 10. It is contemplated however, that a swaybar could nonetheless be used in combination with the valves 145. Theremaining one of the outlets of the manifold 136 is connected to a valve147, which is connected to a T-connector 144. The T-connector 144 splitsthe air flow between two air lines 146 connected to the rear air springs70 to supply air to the rear air springs 70. The opening and closing ofthe valve 147 is controlled by the ECU 50. By closing the valve 147, airfrom the front air springs 70 is prevented from moving to the rear airsprings 70 and vice versa, when the vehicle starts to pitch for example.This helps to reduce the tendency of the ATV 10 to pitch. It iscontemplated that the valve 147 could be omitted. It is alsocontemplated that valves 145 (shown in dotted lines), could also beprovided on the air lines 146 connected to the rear air springs 70 toprevent air from one of the rear air springs 70 from moving to the otherone of the rear air springs 70. It is also contemplated that only therear air springs 70 could be provided with valves 145. It is alsocontemplated that the embodiments described above with respect to FIG. 2and below with respect to FIGS. 13 to 15 could also be provided withvalves 145 and/or 146.

Also, as can be seen in FIG. 12A, in this embodiment, the air line 104is connected to an upper half 54A of the air box 54 to further reducethe likelihood of water entering the air compressor 100. A check valve149 has been added between the outlet 148 to the atmosphere and themanifold 136 to prevent the entry of water into the system. It iscontemplated that the check valve 149 could also be provided in theembodiments described above with respect to FIG. 2 and below withrespect to FIGS. 13 to 15.

In the embodiment shown in FIG. 13, both the front and rear suspensionassemblies 26, 28 are provided with air springs 70. However, in thisembodiment, the manifold 136 has two outlets to the air springs 70. Thevalve 150 controls the air flow through the outlets of the manifold 136.One of the outlets is connected to the two front air springs 70 (airsprings #1, 2), and the other of the outlets is connected to the tworear air springs 70 (air springs #3, 4). Each pair of air springs 70 isprovided with its own high pressure sensor 140. Accordingly, the usercan select an air pressure for the front air springs 70 which isdifferent from the air pressure for the rear air springs 70.

In the embodiment shown in FIG. 14, both the front and rear suspensionassemblies 26, 28 are provided with air springs 70. However, in thisembodiment, the manifold 136 has four outlets to the air springs 70. Thevalve 150 controls the air flow through the outlets of the manifold 136.Each of the outlets is connected to one of the air springs 70. Each airspring 70 is provided with its own high pressure sensor 140.Accordingly, the user can select different air pressures for each of theair springs 70. It is contemplated that instead of selecting airpressures for each to the air springs 70, that the user could select adegree and direction of tilt of the ATV 10 and that the ECU 50 wouldcontrol the air compressor 100 and valve 150 accordingly.

In the embodiment shown in FIG. 15, either the front or the rearsuspension assemblies 26, 28 are provided with air springs 70, althoughit is contemplated that both could be provided with air springs 70. Inthis embodiment, the ATV 10 is provided with a suspension positionsensor 154. The suspension position sensor 154 is connected to one ofthe suspension assemblies 26 or 28 having an air spring 70 so as tosense a degree of compression of the associated air spring 70 and sendsa signal indicative of this position to the ECU 50. For example, asshown in FIG. 6, the suspension position sensor 154 is connected to theright swing arm 68. It is contemplated that multiple suspension positionsensors 154 could be used (one for each suspension assembly 26, 28having an air spring 70 for example), and that the suspension positionsensor 154 could be connected to other portions of the suspensionassemblies 26, 28. The amount by which the air spring 70 is compressedis known as sag. The sag is also indicative of the height of the frame12 relative to the ground. In this embodiment, instead of selecting anair pressure, the user uses the set button 48 to select a desired height(either preset or any value within a range). This desired height isindicated on the gauge 44 (see the scale on the right hand side of thegauge 44 in FIG. 3). The ECU 50 then controls the air compressor 100 andthe valve 150 to adjust the air pressure inside the air springs 70 untilthe desired height is obtained. While the ATV 10 is in motion, the ECU50 would determine the height using a method similar to the methoddescribed above to determine an air pressure inside the air springs 70while the ATV 10 is in motion. Since the control of the compressor 100and the valve 150 is based on readings from the suspension positionsensor 154, no high pressure sensor 140 is provided in this embodiment.However, it is contemplated that a high pressure sensor 140 could beprovided.

It is contemplated that in FIGS. 2, 12B, and 13 to 15 discussed above,that the filter 106 could be substituted by the filter 55, or some otherfilter, in embodiments where the filter 106 is omitted.

Modifications and improvements to the above-described embodiments of thepresent invention may become apparent to those skilled in the art. Theforegoing description is intended to be exemplary rather than limiting.The scope of the present invention is therefore intended to be limitedsolely by the scope of the appended claims.

What is claimed is:
 1. A vehicle comprising: a frame; at least one frontwheel connected to the frame; at least one front suspension assemblyconnecting the at least one front wheel to the frame; at least one rearwheel connected to the frame; at least one rear suspension assemblyconnecting the at least one rear wheel to the frame, at least one of theat least one front and at least one rear suspension assemblies includingan air spring; a seat connected to the frame; a steering assemblyoperatively connected to the at least one front wheel; an engineconnected to the frame and operatively connected to at least one of thewheels; an air intake system fluidly communicating with the engine, theair intake system including an air box; an air compressor connected tothe frame and fluidly communicating with the at least one air spring forselectively supplying air to the at least one air spring, an inlet ofthe air compressor fluidly communicating with the air intake system,during operation of the air compressor to supply air to the at least oneair spring, the air compressor drawing air from the air intake systemand simultaneously supplying the air to the at least one air spring; anair line fluidly connecting the air compressor to the air box; an airfilter disposed inside the air box upstream of an outlet of the air boxto the air line; and a control unit electrically connected to the aircompressor for controlling an operation of the air compressor.
 2. Thevehicle of claim 1, wherein the air box includes an upper half and alower half; and wherein the air line is connected to the upper half ofthe air box.
 3. The vehicle of claim 1, further comprising a manifoldfluidly connected to the air compressor and the at least one air spring;wherein air from the air compressor is supplied to the manifold prior tobeing supplied to the at least one air spring.
 4. The vehicle of claim3, further comprising: a valve selectively fluidly communicating the atleast one air spring with an outlet to the atmosphere for releasing airfrom the at least one air spring, the outlet to the atmosphere fluidlycommunicating with the manifold, air from the at least one air springbeing supplied to the manifold prior to being supplied to the outlet tothe atmosphere, the control unit being electrically connected to thevalve for controlling a position of the valve; and a check valve fluidlydisposed between the outlet to the atmosphere and the manifold, thecheck valve permitting fluid flow from the manifold to the outlet to theatmosphere and preventing fluidly flow from the outlet to the atmosphereto the manifold.
 5. The vehicle of claim 1, further comprising: a valveselectively fluidly communicating the at least one air spring with anoutlet to the atmosphere for releasing air from the at least one airspring, the control unit being electrically connected to the valve forcontrolling a position of the valve; and a selector for selecting avalue of an attribute associated with the at least one air spring, thecontrol unit receiving a signal indicative of the value from theselector and controlling the operation of the air compressor and theposition of the valve selectively fluidly communicating the at least oneair spring with the outlet to the atmosphere based at least on thevalue.
 6. The vehicle of claim 1, wherein: the at least one front wheelis two front wheels; the at least one front suspension assembly is twofront suspension assemblies; and the steering assembly is operativelyconnected to the two front wheels.
 7. The vehicle of claim 6, wherein:the at least one rear wheel is two rear wheels; the at least one rearsuspension assembly is two rear suspension assemblies; the at least oneair spring is at least two air springs; and the engine is operativelyconnected to at least two of the wheels.
 8. The vehicle of claim 1,wherein the at least one front suspension assembly includes the airspring; wherein the at least one rear suspension assembly includes anair spring; and wherein the air compressor is disposed longitudinallybetween the air spring of the at least one front suspension assembly andthe air spring of the at least one rear suspension assembly.
 9. Avehicle comprising: a frame; at least one front wheel connected to theframe; at least one front suspension assembly connecting the at leastone front wheel to the frame; at least one rear wheel connected to theframe; at least one rear suspension assembly connecting the at least onerear wheel to the frame, at least one of the at least one front and atleast one rear suspension assemblies including an air spring; a seatconnected to the frame; a steering assembly operatively connected to theat least one front wheel; an engine connected to the frame andoperatively connected to at least one of the wheels; an air intakesystem fluidly communicating with the engine; an air compressorconnected to the frame and fluidly communicating with the at least oneair spring for selectively supplying air to the at least one air spring,the air compressor being located below the seat, an inlet of the aircompressor fluidly communicating with the air intake system, duringoperation of the air compressor to supply air to the at least one airspring, the air compressor drawing air from the air intake system andsimultaneously supplying the air to the at least one air spring; and acontrol unit electrically connected to the air compressor forcontrolling an operation of the air compressor.
 10. The vehicle of claim9, wherein the air compressor is disposed higher than a center of the atleast one front and the at least one rear wheels.
 11. The vehicle ofclaim 9, wherein the air intake system includes an air box; and furthercomprising an air line fluidly connecting the air compressor to the airbox.
 12. The vehicle of claim 11, wherein the air box includes an upperhalf and a lower half; and wherein the air line is connected to theupper half of the air box.
 13. The vehicle of claim 11, furthercomprising an air filter disposed inside the air box upstream of anoutlet of the air box to the air line.
 14. A vehicle comprising: aframe; at least one front wheel connected to the frame; at least onefront suspension assembly connecting the at least one front wheel to theframe; at least one rear wheel connected to the frame; at least one rearsuspension assembly connecting the at least one rear wheel to the frame,at least one of the at least one front and at least one rear suspensionassemblies including an air spring; a seat connected to the frame; asteering assembly operatively connected to the at least one front wheel;an engine connected to the frame and operatively connected to at leastone of the wheels; an air intake system fluidly communicating with theengine; an air compressor connected to the frame and fluidlycommunicating with the at least one air spring for selectively supplyingair to the at least one air spring, an inlet of the air compressorfluidly communicating with the air intake system, during operation ofthe air compressor to supply air to the at least one air spring, the aircompressor drawing air from the air intake system and simultaneouslysupplying the air to the at least one air spring; a control unitelectrically connected to the air compressor for controlling anoperation of the air compressor; and an auxiliary air output fluidlycommunicating with the air compressor for selectively supplying air fromthe air compressor to a device other than the at least one air spring,auxiliary air output being located under the seat.
 15. The vehicle ofclaim 14, wherein the seat is one of removable and pivotable to provideaccess to the auxiliary air output.
 16. The vehicle of claim 14, whereinthe air intake system includes an air box; and further comprising an airline fluidly connecting the air compressor to the air box.
 17. Thevehicle of claim 16, wherein the air box includes an upper half and alower half; and wherein the air line is connected to the upper half ofthe air box.
 18. The vehicle of claim 16, further comprising an airfilter disposed inside the air box upstream of an outlet of the air boxto the air line.